diff --git a/package.json b/package.json
index 8897e21..5d10c22 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "rimraf": "5.0.5",
     "tsconfig-plantain": "0.0.2",
     "tsx": "3.12.10",
-    "typescript": "5.3.3",
+    "typescript": "5.4.2",
     "vscode": "1.1.37"
   },
   "scripts": {
@@ -34,6 +34,6 @@
   ],
   "private": true,
   "typeCoverage": {
-    "atLeast": 99.5
+    "atLeast": 99.52
   }
 }
diff --git a/packages/cli/src/index.ts b/packages/cli/src/index.ts
index 56be2e0..b5f3008 100644
--- a/packages/cli/src/index.ts
+++ b/packages/cli/src/index.ts
@@ -362,7 +362,7 @@ async function saveHistory(percentage: number, historyFile?:string) {
     const historyFilePath = path.resolve(process.cwd(), historyFile);
     if (await existsAsync(historyFilePath)) {
       const date = new Date().toISOString()
-      const historyFile = JSON.parse((await readFileAsync(historyFilePath)).toString());
+      const historyFile: Record<string, number> = JSON.parse((await readFileAsync(historyFilePath)).toString());
       historyFile[date] = percentage
       await writeFileAsync(historyFilePath, JSON.stringify(historyFile, null, 2) + '\n');
     } else {
diff --git a/packages/core/src/checker.ts b/packages/core/src/checker.ts
index 005747d..8e881d7 100644
--- a/packages/core/src/checker.ts
+++ b/packages/core/src/checker.ts
@@ -139,9 +139,7 @@ function checkTypeAssertion(node: ts.Node, context: FileContext, kind: FileAnyIn
         return
       }
       // exclude safe type assertion powered by isTypeAssignableTo
-      const checker = context.checker as unknown as {
-        isTypeAssignableTo?: (type1: ts.Type, type2: ts.Type) => boolean
-      } & typeof context.checker
+      const checker = context.checker
       if (checker.isTypeAssignableTo
         && checker.isTypeAssignableTo(checker.getTypeAtLocation(node.expression), checker.getTypeFromTypeNode(node.type))) {
         return
diff --git a/packages/plugin/src/index.ts b/packages/plugin/src/index.ts
index 181e4c7..41533f2 100644
--- a/packages/plugin/src/index.ts
+++ b/packages/plugin/src/index.ts
@@ -8,14 +8,15 @@ function init(modules: { typescript: typeof tsserverlibrary }) {
     const proxy: tsserverlibrary.LanguageService = {
       ...info.languageService,
       getSemanticDiagnostics(fileName) {
-        if (!info.config?.jsEnable && (fileName.endsWith('.js') || fileName.endsWith('.jsx'))) {
+        const config: { jsEnable: boolean } = info.config
+        if (!config?.jsEnable && (fileName.endsWith('.js') || fileName.endsWith('.jsx'))) {
           return []
         }
         const result = lintSync(
           info.project.getCompilerOptions(),
           info.project.getRootFiles(),
           {
-            ...info.config,
+            ...config,
             files: [fileName],
             oldProgram,
           },
diff --git a/yarn.lock b/yarn.lock
index db4ac32..f73f163 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2032,6 +2032,11 @@ typescript@5.3.3:
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.3.3.tgz#b3ce6ba258e72e6305ba66f5c9b452aaee3ffe37"
   integrity sha512-pXWcraxM0uxAS+tN0AG/BF2TyqmHO014Z070UsJ+pFvYuRSq8KH8DmWpnbXe0pEPDHXZV3FcAbJkijJ5oNEnWw==
 
+typescript@5.4.2:
+  version "5.4.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.4.2.tgz#0ae9cebcfae970718474fe0da2c090cad6577372"
+  integrity sha512-+2/g0Fds1ERlP6JsakQQDXjZdZMM+rqpamFZJEKh4kwTIn3iDkgKtby0CeNd5ATNZ4Ry1ax15TMx0W2V+miizQ==
+
 uc.micro@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/uc.micro/-/uc.micro-2.0.0.tgz#84b3c335c12b1497fd9e80fcd3bfa7634c363ff1"